Inverse emulsion polymers are commonly used as polymeric flocculants for the separation of fine particulate matter suspended in a liquor or slurry obtained during mineral extraction. Inverse emulsion polymers are typically water-in-oil emulsions produced by a polymerization technique to form a finely divided aqueous solution of a water soluble polymer dispersed in an oil. Polymeric flocculants separate suspended particulate matter by coalescing the fine particles to form larger aggregates. The increased size of the aggregates causes the aggregates to settle at a reasonable rate, thereby clarifying the liquor. Purification of a liquid in this manner is accomplished by the process of sedimentation, which is typically conducted in large vessels (e.g., settlers or clarifiers) specifically designed for this purpose.
Conventional hydrocarbon-based or paraffinic-based polymer flocculants tend to have a deleterious effect on the liquor as well as on systems, equipment or processes downstream of the separation process. The hydrocarbon-based oil phase enriches the liquor with increased amounts of organic matter which impedes subsequent processing of the liquor. Furthermore, use of hydrocarbon-based polymeric flocculants in liquors and/or water systems at elevated temperature and/or elevated pressures is limited as the volatility of the hydrocarbon oil phase under such conditions carries substantial risk of explosion and contamination of the water condensate obtained during the mineral processing process.
A need therefore exists for an inverse emulsion polymer that does not adversely effect the quality or retrieval of a subsequent product from a water system or liquor to which the emulsion polymer is applied. A need further exists for a safe and effective inverse emulsion polymer for application to water systems or liquors at elevated temperature and/or elevated pressure.